Propulsion devices

ABSTRACT

A water-borne vessel has an intake duct provided by a formed section of the hull. An impeller unit comprising a rotary impeller within a casing fixed to a discharge duct is fastened to the hull at the outlet of the intake duct.

United States Patent 1191 Usborne July 16, 1974 1 PROPULSION DEVICES 3,233,573 2/1966 3,251,185 5/1966 [75] Inventor: Andrew Charles Usborne, Sheffield, 3,279,180 [0/1966 land 3,347,045 /1967 [73] Assignee: UA Engineering Limited, Sheffield,

E l d Primary Examiner-Trygve M. Blix Flled! 1971 Assistant Examiner-Stuart M. Goldstein [211 App! No: 190 799 Attorney, Agent, or Firm-Young & Thompson Foreign Application Priority Data 001. 20, 1970 Great Britain 49639/- ABSTRMIT [52] US. Cl. -/16 A water-borne vessel has an intake duct provided by a [51] Int. Cl B63h 11/08 formed section of the'hull. An impeller unit compris- [58] Field of Search 115/53, l6, ll, 14 ing a rotary impeller within a casing fixed to a discharge duct is fastened to the hull at the outlet of the [56] References Cited intake duct.

UNITED STATES PATENTS 2,993,463 4 Claims, 2 Drawing Figures 7/1961 McKinney ..115/16 PROPULSION DEVICES FIELD OF THE INVENTION BACKGROUND OF THE INVENTION At present hydraulic jet propulsion devices for waterborne vessels are manufactured and supplied as a complete unit which is ready for fitting to the vessel and coupling to an engine which, in use, drives a rotary impeller within a duct in the device.

It is an object of the invention to simplify the installation of a jet propulsion device in a water-borne vessel.

SUMMARY or THE INVENTION An intake duct is provided by a'formed section of the vesselhull adjacent the rear thereof and the propulsion device is fastened to the hull at the outlet end of the intake duct. The propulsion device is formed as a unit I BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a hydraulic jet propulsion device for a water-borne vessel, part of the rear of the vessel being shown in outline, and

FIG, 2 is a sectional view of the device.

7 DESCRIPTION OF THE PREFERRED EMBODIMENTS The vessel hull 10 shown in the drawings is moulded from glass-fibre-reinforced polyester resin with a rear section formed to provide an intake duct 11 which sweeps upwardly and rearwardly from a bottom intake opening 12 to a rear transom 13 at the bottom of which the duct outlet 14 is formed. Within the formed section and above the intake opening 12 there is a mounting 15 for a shaft bearing and seal assembly 16 disposed in line with the centre of the circular outlet 14. l I

The assembly 16 includes a main body 17 having an end face 18 in which a plurality of tapped apertures (not shown) are formed for the reception of threaded fasteners for attachment of the body 17 to a wall 19 of the formed section. The body 17 is formed integrally with a flange 20 the configuration of which is such that and bears against the inner element of sealing arrangement 23.

A propulsion unit attached to the formed section comprises a rotary axial flow impeller 29 within'a casing 30 which has a flange 31 which is bolted to the back of the transom 13. The impeller casing is formed integrally with an outlet duct 32 from the rear end of which the propulsion jet issues. The impeller drive shaft 26 extends rearwardly through the intake duct 11 to the casing 30 within which it is supported by a bearing 33 contained within a bearing housing 34 connected by vanes 35 to the outlet duct 32.

The formed hull section provides the side walls and the top wall of the intake duct 11 the bottom wall of which is provided by a'separately fitted member 36 which extends from the rear of the intake opening 12 to the transom 13 thus blanking off part of a bottom opening initially formed in the hull moulding. A plurality of rods, of which one 37 is shown in the drawings, extend forwardly of the member 36 across the intake opening 12 to exclude flotsam and other debris from the intake duct 11. Each rod 37 has its rear end received in a socket in the member 36 and its forward end received in a socket in the formed section of the hull.

The outlet duct 32 carries a steering unit comprising a pair of buckets 38 and the lower portion of the wall of the outlet duct is cut away at 39 to provide a lower discharge opening. A vane 40 is positioned adjacent the lower discharge opening to deflect water issuing therethrough in a forward direction As described in British Patent Specification No. 1,190,735 the two buckets 38 are pivotable about a common vertical axis and are controllable to deflect the water jet issuing through the outlet duct for steering purposes. g

The buckets are also movable into positions in which they close the outlet duct 32 to deflect the jet downwardly through the lower discharge opening and thus forwardly beneath the hull.

As shown the transom 13 is inclined rearwardly and upwardly so that the jet, which, in forwardmovement, issues at right angles to the transom, has a slight downward component.

In an alternative arrangement (not shown) the rear transom is vertical and the impeller shaft passes horizontally through the intake duct to the bearing carried by the formed section. The shaft passes through a circular opening in the wall of the intake duct and the bearing and a seal mechanism are fitted in this opening from within the intake duct.

The arrangement described above may be duplicated on opposite sides of the hull centre line, in which case each steering unit may control steering in only one direction.

I claim:

l. In a water-borne vessel having a hull having a formed rear section including a downwardly facingv channel which has an upwardly rearwardly inclined .upper wall and which affords an intake duct through which water passesduring travel of the vessel, a unit comprising a casing containing an impeller and defining a discharge duct, said unit being fastened to the formed section at the outlet of the intake duct with the two ducts intercommunicating and with the impeller located at the junction between the two ducts, said impeller having a driving shaft which projects forwardly of the vessel and passes through an opening in said formed section of the hull such that the forward end of the shaftis accessible from within the hull for coupling to a driving engine, and support and bearing means located at the junction between said ducts for rotatably supporting said impeller; the improvement in which said upper wall of said intake duct has a recess therein between two upwardly rearwardly inclined portions of said upper wall, said recess having a forward wall that is transverse to said shaft, said opening for said shaft extending through said forward wall, a forward bearing for said shaft, said forward bearing comprising a body that has a forward surface that abuts the rear surface of said forward wall about said opening, and a flange on the rear side of said bearing body, said flange being upwardly rearwardly inclined and having a rear surface that forms a continuation of said two portions of said upper wall of said intake duct thereby to close said recess without obstructing flow of water through the intake duct.

2. The combination according to claim 1, wherein the support and bearing means for the impeller comprises a bearing contained within a casing located centrally of the discharge duct and supported therein by radially extending vanes.

3. The combination according to claim 1, wherein the body of the shaft bearing has a throughbore for reception of the impeller driving shaft, said throughbore containing a roller bearing and sealing means surrounding the shaft on either side of the roller bearing.

4. The combination according to claim 3, wherein the forward end portion of the impeller driving shaft is threaded and an internally threaded sleeve-like spacer is fitted on said threaded end portion of the shaft so as to bear against the adjacent sealing means. 

1. In a water-borne vessel having a hull having a formed rear section including a downwardly facing channel which has an upwardly rearwardly inclined upper wall and which affords an intake duct through which water passes during travel of the vessel, a unit comprising a casing containing an impeller and defining a discharge duct, said unit being fastened to the formed section at the outlet of the intake duct with the two ducts intercommunicating and with the impeller located at the junction between the two ducts, said impeller having a driving shaft which projects forwardly of the vessel and passes through an opening in said formed section of the hull such that the forward end of the shaft is accessible from within the hull for coupling to a driving engine, and support and bearing means located at the junction between said ducts for rotatably supporting said impeller; the improvement in which said upper wall of said intake duct has a recess therein between two upwardly rearwardly inclined portions of said upper wall, said recess having a forward wall that is transverse to said shaft, said opening for said shaft extending through said forward wall, a forward bearing for said shaft, said forward bearing comprising a body that has a forward surface that abuts the rear surface of said forward wall about said opening, and a flange on the rear side of said bearing body, said flange being upwardly rearwardly inclined and having a rear surface that forms a continuation of said two portions of said upper wall of said intake duct thereby to close said recess without obstructing flow of water through the intake duct.
 2. The combination according to claim 1, wherein the support and bearing means for the impeller comprises a bearing contained within a casing located centrally of the discharge duct and supported therein by radially extending vanes.
 3. The combination according to claim 1, wherein the body of the shaft bearing has a throughbore for reception of the impeller driving shaft, said throughbore containing a roller bearing and sealing means surrounding the shaft on either side of the roller bearing.
 4. The combination according to claim 3, wherein the forward end portion of the impeller driving shaft is threaded and an internally threaded sleeve-like spacer is fitted on said threaded end portion of the shaft so as to bear against the adjacent sealing means. 